[meteorite-list] meteorite slices

From: James Tobin <jimmypaul_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:57 2004
Message-ID: <3FF84E32.A9D73E2E_at_earthlink.net>

Hello List,
Gee it has been awhile since I posted to the list.
My article this month in MeteoriteTimes is on cutting and maybe a little
helpful. It mostly describes the cutting process and how I do lapping
after cutting. So here is a little more info.

It is very possible and actually fairly easy to smooth off a slice using
the wet and dry type of aluminum oxide sandpaper. I used it years ago
before I made the lapping equipment. Use it dry and be careful about the
dust created. It comes in many grits. Start with the 150 and go to 350
or 400, then use 600 and lastly 800. Keep the old worn out paper since
it continues to work a little and the worn out 800 gives a nice pre
polish. I used a piece of hard smooth plastic to stroke the slice on so
that it did not get the turned down edge.

Polishing can be done on a piece of leather with any of the synthetic
alumina based polished. They are white and don't stain the slice like
rouge or cerium oxide. Clean up is easy. You will need to make a slurry
of the polish about the consistency of heavy cream. Use distilled water
to make the liquid. Stroke randomly around on the hard leather using
firm finger pressure. Not so much as to crack the slice though.

One point though which I also make in the article is, not all meteorites
are enhanced by high polishing. Some lose visible detail as the matrix
darkens with polishing. But, to be sure all slices should be smooth and
saw mark free before selling.

Happy New Year by the way, and looking forward to seeing many of you in
Tucson. Jim

-- 
Jim Tobin
jim_at_meteorite.com
The Meteorite Exchange, Inc.
PMB 455 PO Box 7000
Redondo Beach, CA 90277 USA
www.meteorite.com

Received on Sun 04 Jan 2004 12:32:34 PM PST